body{
    min-height: 100%;
   overflow-x: hidden;
}
.start-page {
    font-size: 30px;
    height: 300px;
    line-height: 300px;
    color: #ccc;
    text-align: center;
    margin-top:150px;
}
.left-panel{
    min-height: 100vh;
    position: relative;
}
.button-group{
    position: absolute;
    width: 100%;
    bottom: 0;
}
.no-border{
    border-radius: 0;
}
.file-item{
    cursor: pointer;
}